Professor Eric Shepherd is a chartered scientist, forensic psychologist, counselling psychologist, and psychotherapist. Originally a career intelligence officer he has held a wide range of clinical and academic appointment. He has worked with the police within and outside UK, with the legal profession, with government departments (including the UK Ministry of Defence, the Serious Fraud Office, and HM Revenue and Customs), and with the private sector (including banks, insurers, telecommunications providers and the petrochemical industry). He was a member of the UK Home Office Working Party on Investigative Interviewing. He is co-editor of Witness Testimony and Analysing Witness Testimony (OUP).; Dr Andy Griffiths is a police officer with over 25 years' experience as a detective, rising to the rank of Detective Superintendent leading homicide, organised crime and intelligence departments. He has also been involved in training police officers for the majority of his career, and served as a member of the Association of Chief Police Officers strategic interview steering group in England and Wales for over a decade. He was awarded his PhD for research into the effectiveness of specialized interview training in real life major crime cases and has advised police forces both in the UK and numerous countries worldwide.